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In this study, we used a simple and low-toxicity chemical treatment to make a carboxylate-functionalized dragon fruit peel powder (CF-DFPP) from dragon fruit peel to improve its capacity for adsorbing Rhodamine B (RhB) from an aqueous medium. Field Emission-Scanning Electron Microscopy/Energy-Dispersive X-ray (FE-SEM/EDX), point of zero charges (pH

Uranium (U(VI)) is radioactive and the primary raw material in the production of nuclear energy. Hence the research associated with uranium removal gained a lot of importance because to reduce the threat of uranium contamination to ecology and its environment surroundings. Thus, economically as well as environmentally friendly sorbents with a good sorption capacity have to be acquired for the removal of U(VI) pollutants from the aqueous and polluted sea samples. In this study magnetic- Momordica charantia leaf powder impregnated into chitosan (m-MCLPICS) was prepared through the impregnation method. After preparation the adsorbent undergone through various characterizations such as BET, XRD, FTIR, SEM with elemental mapping, and VSM analysis. The specific surface area (93.12 m2/g), pore size (0.212 cm3/g) and pore volume (15.35 nm) of m-MCLPICS was obtained from the BET analysis. A pH value of 5 and 0.5 g of adsorbent dose were selected as an optimum values for U(VI) removal. Kinetic data follows the pseudo-second-order model, and the equilibrium data fitted well with the Langmuir isotherm model. ΔG° (−1.6999, −2.4994, −3.5476 and −4.5147 kJ/mol), ΔH0 (25.1 kJ/mol) and ΔS0 (0.089 kJ/mol K) indicates that the U(VI) sorption process is feasible, spontaneous and endothermic.

In this study m-AHLPICS (magnetic Arachis hypogaea leaves powder impregnated into chitosan) was prepared and utilized as an adsorbent to remove U(VI) from aqueous and real polluted wastewater samples. m-AHLPICS was characterized by using the BET, XRD, FTIR, SEM with elemental mapping and magnetization measurements. Different experimental effects such as pH, dose, contact time, and temperature were considered broadly. Chitosan modified magnetic leaf powder (m-AHLPICS) exhibits an excellent adsorption capacity (232.4 ± 5.59 mg/g) towards U(VI) ions at pH 5. Different kinetic models such as pseudo-first-order, and pseudo-second-order models were used to know the kinetic data. Langmuir, Freundlich and D-R isotherms were implemented to know the adsorption behavior. Isothermal information fitted well with Langmuir isotherm. Kinetic data followed by the pseudo-second-order kinetics (with high R2 values, i.e., 0.9954, 0.9985 and 0.9971) and the thermodynamic data demonstrate that U(VI) removal using m-AHLPICS was feasible, and endothermic in nature.

A novel, eco-friendly aminated chitosan Schiff’s base (ACSSB@ZnO) was developed and utilized to remove MO from aqueous environment. The impact of different significant parameters, for example, pH (3–11), adsorbent dose (0.1–0.6 g), contact time (0–120 min), and temperature (303–323 K) have been explored by batch process. Kinetic data was illustrated by pseudo-second-order model and the isotherms fitted well with Langmuir isotherm model. The highest sorption capacity of ACSSB@ZnO was observed to be 111.11 mg/g at 323 K. Positive enthalpy and entropy values demonstrated that the MO adsorption procedure was an endothermic. Negative Gibbs free energy values implied the spontaneous nature of the adsorption system. Moreover, reusability experiments were studied and it can be regenerated by using NaOH as effluent.

In this study, two Fusarium strains namely ZSY and MJY were successfully isolated from the contaminated soil of Dabaoshan smelter in Shaoguan City, and utilised as a biosorbent for the removal of Pb(II) ions from aqueous solution. Effect of pH (6), agitation speed (150 rpm), biomass concentration (1 g/L), initial Pb(II) concentration, contact time (60 min), and effect of temperature (323 K) was investigated. Kinetic and isotherm results showed that the removal of Pb(II) ions onto ZSY and MJY were fitted well with the pseudo-second-order and Langmuir isotherm models (232.56 and 263.16 mg/g). In addition thermodynamic studies were also discussed.

As pyrazoles are familiar for showing various biological properties, a series of novel isocoumarin tethered carbothioamide linked pyrazole derivatives were prepared successfully in the presence of environmental favor conditions and evaluated for their pathogenic resistance against four bacteria and two fungi, showing significant activity against different microbial except compound 5d. Among the active compounds, 5f displayed highest antimicrobial property. In fact, 5b and 5l motifs showing good inhibitory activity. Further, a detailed structure activity relationship also discussed, which revealed that the presence of electron withdrawing -NO2 group in 5f compound may delivered highest biological property, while the amino group attached in compound 5d delivered inactive antibacterial property. Moreover, computer aided studies of biologically effective compounds to determine the interactions and docking score with the crystal structure of Escherichia coli 24 kDa DNA gyrase subunit B in complex with clorobiocin. It was observed that the amino acid residues present in the active binding site of the protein1KZN can frequently interact with targets.

Removal of metals from wastewaters causes a big concern from the environmental point of view due to their extreme toxicity towards aquatic life and humans. Application of As(III) from aqueous solution by ZnO nanorods as adsorbent has been investigated in the present study. The synthesized nanorods were characterized by XRD, FT-IR spectroscopy, SEM, and thermogravimetric analysis. Optimum biosorption conditions were determined with respect to pH, adsorbent dose, contact time, and temperature. The experimental data were examined using the Lagergren’s first-order, pseudo-second-order and intraparticle diffusion kinetic models. The results revealed that the pseudo-second-order kinetic model provided the best description of the data. Langmuir and Freundlich isotherm models were applied to the equilibrium data. The maximum As(III) sorption capacity of ZnO nanorods was found to be 52.63 mg/g at pH 7, adsorbent dose 0.4 g, contact time 105 min, and temperature 323 K. The calculated thermodynamic parameters, ΔG o (between − 5.741, − 5.342 and − 4.538 kJ/mol at 303–323 K), ∆H o (13.75 kJ/mol) and ∆S o (0.0616 J/mol K) showed that the sorption of As(III) onto ZnO nanorods was feasible, spontaneous and exothermic, respectively.

It is well-known that heavy metals are non-biodegradable and have been showing remarkable impacts on the environment, public health and economics. Because of high toxic tendency, lead (Pb), is one of the foremost considerable hazardous metal with high environmental impacts. Chitosan is a polysaccharide, and can be utilized in wastewater treatment because of its good sorption ability. Amino and hydroxyl groups (C-3 position) on chitosan can serve as electrostatic interaction and complexation sites for metal cations. Chemical crosslinking can effectively enhance the stability of chitosan in acidic media. Hence a novel, cost-effective and eco-friendly ZnO incorporated into aminated chitosan Schiff's base (ACSSB@ZnO) has been synthesized, characterized (BET, XRD, FTIR, SEM, TEM and 1H NMR), and utilized as an adsorbent for the removal of Pb(II) ions from the aqueous environment. The various operating parameters, such as pH (2–8), agitation speed (30–180), adsorbent dose (0.1–0.8 g), contact time (0–140 min), metal ion concentration and temperature (303−323 K) were investigated. The maximum sorption capacity of Pb(II) onto ACSSB@ZnO was found to be 55.55 mg/g. The equilibrium, and kinetic studies suggested that the adsorption process followed the Langmuir isotherm and Pseudo-Second-Order model. Thermodynamic data showed that the sorption process was feasible, spontaneous, and endothermic.

Solanum melongena leaves are relatively galore and used as inexpensive material. This paper presents the characterization and evaluation of potential of S. melongena leaf powder (SMLP) for removal of Pb(II) from aqueous solution as a function of pH, biomass dosage, initial metal ion concentration, contact time and temperature. Experimental data were analyzed in terms of three kinetic models such as the pseudo-first-order, pseudo-second-order and intraparticle diffusion models and the results showed that the biosorption processes of Pb(II) followed well pseudo-second-order kinetics. Langmuir and Freundlich isotherm models were applied to describe the biosorption process. Langmuir isotherm described the equilibrium data very well, with a maximum monolayer sorption capacity of 71.42 mg/g for Pb(II) ions at 323 K. The biosorption process was spontaneous and endothermic in nature with negative Δ G ° (−8.746, −8.509 and −7.983 kJ/mol) and positive value for Δ H ° (3.698 kJ/mol).

This study investigates the equilibrium, kinetics and thermodynamics of Nickel(II) biosorption from aqueous solution by the fungal mat of Trametes versicolor (rainbow) biomass. The optimum biosorption conditions like pH, contact time, biomass dosage, initial metal ion concentration and temperaturewere determined in the batch method. The biosorbent was characterized by FTIR, SEM and BET surface area analysis. The experimental data were analyzed in terms of pseudo-first-order, pseudo-secondorder and intraparticle diffusion kinetic models, further it was observed that the biosorption process of Ni(II) ions closely followed pseudo-second-order kinetics. The equilibrium data of Ni(II) ions at 303, 313, and 323 K were fitted to the Langmuir and Freundlich isotherm models. Langmuir isotherm provided a better fit to the equilibrium data andthe maximum monolayer biosorption capacity of the T. versicolor(rainbow) biomass for Ni(II) was 212.5 mg/g at pH 4.0. The calculated thermodynamic parameters, ΔG○, ΔH○, and ΔS○, demonstrated that the biosorption of Ni(II) ions onto the T. versicolor (rainbow) biomass was feasible, spontaneous and endothermic at 303 ∼ 323 K. The performance of the proposed fungal biosorbent was also compared with that of many other reported sorbents for Nickel(II) removal and it was observed that the proposed biosorbent is effective in terms of its high sorption capacity.

The ability of Caesalpinia bonducella leaf powder has been utilized as an inexpensive biosorbent for the removal of Cu(II) from aqueous media. Optimum biosorption conditions were found to be pH 5.0, adsorbent dosage 0.07 g/L, agitation speed 180 rpm, and equilibrium time 120 min. Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, and X-ray diffraction were used to characterize the surface functional groups, structure, compositional analysis, and crystallinity of the biosorbent. FT-IR analysis shows the involvement of various functional groups such as hydroxyl, amide, carboxyl, and carbonyl groups in the removal of Cu(II) from aqueous environment. Kinetic data were fitted well to a pseudo-second-order kinetic model compared to pseudo-first-order and intraparticle diffusion kinetic models. The equilibrium data were well fitted by the Langmuir isotherm model by revealing the maximum sorption capacity of 76.92 mg/g.

Present research discussed the utilization of aminated pumpkin seed powder (APSP) as an adsorbent for methyl orange (MO) removal from aqueous solution. Batch sorption experiments were carried to evaluate the influence of pH, initial dye concentration, contact time, and temperature. The APSP was characterized by using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). The experimental equilibrium adsorption data were fitted using two two-parameter models (Langmuir and Freundlich) and two three-parameter models (Sips and Toth). Langmuir and Sips isotherms provided the best model for MO adsorption data. The maximum monolayer sorption capacity was found to be 200.3mg/g based on the Langmuir isotherm model. The pseudo-first-order and pseudo-second-order model equations were used to analyze the kinetic data of the adsorption process and the data was fitted well with the pseudo-second-order kinetic model (R(2)>0.97). The calculated thermodynamic parameters such as ΔG(0), ΔH(0) and ΔS(0) from experimental data showed that the sorption of MO onto APSP was feasible, spontaneous and endothermic in the temperature range 298-318 K. The FTIR results revealed that amine and carboxyl functional groups present on the surface of APSP. The SEM results show that APSP has an irregular and porous surface which is adequate morphology for dye adsorption. Desorption experiments were carried to explore the feasibility of adsorbent regeneration and the adsorbed MO from APSP was desorbed using 0.1M NaOH with an efficiency of 93.5%. Findings of the present study indicated that APSP can be successfully used for removal of MO from aqueous solution.

The biosorption characteristics of Pb(II) and Cd(II) ions from aqueous solution using the fungus (Trametes versicolor) biomass were investigated as a function of pH, biomass dosage, contact time, initial metal ion concentration and temperature. Langmuir and Freundlich models were applied to describe the biosorption of the metal ions by fungus (T. versicolor) biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The monolayer biosorption capacity of T. versicolor biomass for Pb(II) and Cd(II) ions was found to be 208.3 mg g−1 and 166.6 mg g−1, respectively. The calculated thermodynamic parameters (ΔG°, ΔH° and ΔS°) showed that the biosorption of both metal ions was feasible, spontaneous and endothermic at 303–323 K. Experimental data were also used to study biosorption kinetics using pseudo-first-order, pseudo-second-order and intraparticle diffusion kinetic models. The results showed that the biosorption processes of both metal ions followed well pseudo-second-order kinetics.

Chitosan-coated perlite (CCP) beads were prepared by dropwise addition of a liquid slurry containing chitosan and perlite to an alkaline bath. The resulting beads were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and surface area analysis. The chitosan content of the beads is 23% as determined by a pyrolysis method. Adsorption of phenolic compounds (phenol, 2-chlorophenol, and 4- chlorophenol) from aqueous solutions on chitosan-coated perlite beads was studied under batch equilibrium and column flow conditions. The binding capacity of the biosorbent was investigated as a function of initial pH, contact time, initial concentration of adsorbate, and dosage of adsorbent. Adsorption kinetic and isotherm studies, respectively, showed that the adsorption process followed a pseudo-first-order kinetic model and the Langmuir isotherm. The maximum monolayer adsorption capacity of phenol, 2-CP, and 4-CP on to the chitosan-coated perlite beads was found to be...

Calcium alginate-chitosan (CA/CS) blended membranes were prepared and crosslinked with maleic anhydride (MA) for the pervaporation (PV) separation of ethylene glycol (EG)/water mixtures at 30°C. The structure and properties of blend membranes were studied with the aid of FTIR, XRD, TGA, and SEM. The effect of experimental parameters such as feed composition, membrane thickness, and permeate pressure on separation performance of the MA crosslinked membranes were determined in terms of flux, selectivity, and pervaporation separation index. Sorption studies were carried out to evaluate the extent of interaction and degree of swelling of the blend membranes in pure, as well as in binary mixtures. The experimental results suggested that the crosslinked membrane (M-CA/CS) exhibited a good selectivity of 302 at a normalized flux of 0.38 kg.m− 2.h− 1.10 μ m at 30°C for 96.88 wt% EG aqueous solution.

BACKGROUND: This research focuses on understanding the biosorption process and developing a cost-effective technology for the treatment of water contaminated with phenolic compounds (phenol, 2-chlorophenol and 4-chlorophenol), which are discharged into the aquatic environment from a variety of sources and are highly toxic. In order to remove phenolic compounds from water, a new biobased sorbent is developed, blending chitosan with abrus precatorius, both naturally occurring biopolymers. The resulting chitosan–abrus precatorius blended beads (CS/Ab) were characterized by Brunauer, Emmett and Teller (BET) analysis, Fourier Transform Infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) techniques under batch equilibrium and column flow experimental conditions. The binding capacity of the biosorbent was investigated as a function of initial pH, contact time, initial concentration of adsorbate and dosage of adsorbent. RESULTS: The percentage removal of phenol, 2-CP and 4-CP increased with increasing adsorbent dose, while the adsorption capacity at equilibrium, qe (mg g−1) (amount of phenol, 2-CP and 4-CP loaded per unit weight of adsorbent) decreased. The equilibrium time was found to be 240 min for full equilibration of all adsorbates. Adsorption kinetic and isotherm studies showed that the pseudo-first-order model and the Langmuir isotherm were the best choices to describe the adsorption behaviors. The maximum monolayer adsorption capacity of phenol, 2-CP and 4-CP on to the (CS/Ab) beads was found to be 156 mg g−1, 204 mg g−1 and 278 mg g−1, respectively. CONCLUSION: The experimental results suggested that (CS/Ab) blended beads are effective in the removal of phenolic compounds from aqueous medium. Copyright © 2009 Society of Chemical Industry